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Diffstat (limited to 'fs/namei.c')
-rw-r--r--fs/namei.c209
1 files changed, 117 insertions, 92 deletions
diff --git a/fs/namei.c b/fs/namei.c
index 808e4ea2bb9..28d49b301d5 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -518,18 +518,20 @@ static int __emul_lookup_dentry(const char *, struct nameidata *);
static __always_inline int
walk_init_root(const char *name, struct nameidata *nd)
{
- read_lock(&current->fs->lock);
- if (current->fs->altroot && !(nd->flags & LOOKUP_NOALT)) {
- nd->mnt = mntget(current->fs->altrootmnt);
- nd->dentry = dget(current->fs->altroot);
- read_unlock(&current->fs->lock);
+ struct fs_struct *fs = current->fs;
+
+ read_lock(&fs->lock);
+ if (fs->altroot && !(nd->flags & LOOKUP_NOALT)) {
+ nd->mnt = mntget(fs->altrootmnt);
+ nd->dentry = dget(fs->altroot);
+ read_unlock(&fs->lock);
if (__emul_lookup_dentry(name,nd))
return 0;
- read_lock(&current->fs->lock);
+ read_lock(&fs->lock);
}
- nd->mnt = mntget(current->fs->rootmnt);
- nd->dentry = dget(current->fs->root);
- read_unlock(&current->fs->lock);
+ nd->mnt = mntget(fs->rootmnt);
+ nd->dentry = dget(fs->root);
+ read_unlock(&fs->lock);
return 1;
}
@@ -724,17 +726,19 @@ int follow_down(struct vfsmount **mnt, struct dentry **dentry)
static __always_inline void follow_dotdot(struct nameidata *nd)
{
+ struct fs_struct *fs = current->fs;
+
while(1) {
struct vfsmount *parent;
struct dentry *old = nd->dentry;
- read_lock(&current->fs->lock);
- if (nd->dentry == current->fs->root &&
- nd->mnt == current->fs->rootmnt) {
- read_unlock(&current->fs->lock);
+ read_lock(&fs->lock);
+ if (nd->dentry == fs->root &&
+ nd->mnt == fs->rootmnt) {
+ read_unlock(&fs->lock);
break;
}
- read_unlock(&current->fs->lock);
+ read_unlock(&fs->lock);
spin_lock(&dcache_lock);
if (nd->dentry != nd->mnt->mnt_root) {
nd->dentry = dget(nd->dentry->d_parent);
@@ -1042,15 +1046,17 @@ static int __emul_lookup_dentry(const char *name, struct nameidata *nd)
struct vfsmount *old_mnt = nd->mnt;
struct qstr last = nd->last;
int last_type = nd->last_type;
+ struct fs_struct *fs = current->fs;
+
/*
- * NAME was not found in alternate root or it's a directory. Try to find
- * it in the normal root:
+ * NAME was not found in alternate root or it's a directory.
+ * Try to find it in the normal root:
*/
nd->last_type = LAST_ROOT;
- read_lock(&current->fs->lock);
- nd->mnt = mntget(current->fs->rootmnt);
- nd->dentry = dget(current->fs->root);
- read_unlock(&current->fs->lock);
+ read_lock(&fs->lock);
+ nd->mnt = mntget(fs->rootmnt);
+ nd->dentry = dget(fs->root);
+ read_unlock(&fs->lock);
if (path_walk(name, nd) == 0) {
if (nd->dentry->d_inode) {
dput(old_dentry);
@@ -1074,6 +1080,7 @@ void set_fs_altroot(void)
struct vfsmount *mnt = NULL, *oldmnt;
struct dentry *dentry = NULL, *olddentry;
int err;
+ struct fs_struct *fs = current->fs;
if (!emul)
goto set_it;
@@ -1083,12 +1090,12 @@ void set_fs_altroot(void)
dentry = nd.dentry;
}
set_it:
- write_lock(&current->fs->lock);
- oldmnt = current->fs->altrootmnt;
- olddentry = current->fs->altroot;
- current->fs->altrootmnt = mnt;
- current->fs->altroot = dentry;
- write_unlock(&current->fs->lock);
+ write_lock(&fs->lock);
+ oldmnt = fs->altrootmnt;
+ olddentry = fs->altroot;
+ fs->altrootmnt = mnt;
+ fs->altroot = dentry;
+ write_unlock(&fs->lock);
if (olddentry) {
dput(olddentry);
mntput(oldmnt);
@@ -1102,29 +1109,30 @@ static int fastcall do_path_lookup(int dfd, const char *name,
int retval = 0;
int fput_needed;
struct file *file;
+ struct fs_struct *fs = current->fs;
nd->last_type = LAST_ROOT; /* if there are only slashes... */
nd->flags = flags;
nd->depth = 0;
if (*name=='/') {
- read_lock(&current->fs->lock);
- if (current->fs->altroot && !(nd->flags & LOOKUP_NOALT)) {
- nd->mnt = mntget(current->fs->altrootmnt);
- nd->dentry = dget(current->fs->altroot);
- read_unlock(&current->fs->lock);
+ read_lock(&fs->lock);
+ if (fs->altroot && !(nd->flags & LOOKUP_NOALT)) {
+ nd->mnt = mntget(fs->altrootmnt);
+ nd->dentry = dget(fs->altroot);
+ read_unlock(&fs->lock);
if (__emul_lookup_dentry(name,nd))
goto out; /* found in altroot */
- read_lock(&current->fs->lock);
+ read_lock(&fs->lock);
}
- nd->mnt = mntget(current->fs->rootmnt);
- nd->dentry = dget(current->fs->root);
- read_unlock(&current->fs->lock);
+ nd->mnt = mntget(fs->rootmnt);
+ nd->dentry = dget(fs->root);
+ read_unlock(&fs->lock);
} else if (dfd == AT_FDCWD) {
- read_lock(&current->fs->lock);
- nd->mnt = mntget(current->fs->pwdmnt);
- nd->dentry = dget(current->fs->pwd);
- read_unlock(&current->fs->lock);
+ read_lock(&fs->lock);
+ nd->mnt = mntget(fs->pwdmnt);
+ nd->dentry = dget(fs->pwd);
+ read_unlock(&fs->lock);
} else {
struct dentry *dentry;
@@ -1587,6 +1595,24 @@ int may_open(struct nameidata *nd, int acc_mode, int flag)
return 0;
}
+static int open_namei_create(struct nameidata *nd, struct path *path,
+ int flag, int mode)
+{
+ int error;
+ struct dentry *dir = nd->dentry;
+
+ if (!IS_POSIXACL(dir->d_inode))
+ mode &= ~current->fs->umask;
+ error = vfs_create(dir->d_inode, path->dentry, mode, nd);
+ mutex_unlock(&dir->d_inode->i_mutex);
+ dput(nd->dentry);
+ nd->dentry = path->dentry;
+ if (error)
+ return error;
+ /* Don't check for write permission, don't truncate */
+ return may_open(nd, 0, flag & ~O_TRUNC);
+}
+
/*
* open_namei()
*
@@ -1668,18 +1694,10 @@ do_last:
/* Negative dentry, just create the file */
if (!path.dentry->d_inode) {
- if (!IS_POSIXACL(dir->d_inode))
- mode &= ~current->fs->umask;
- error = vfs_create(dir->d_inode, path.dentry, mode, nd);
- mutex_unlock(&dir->d_inode->i_mutex);
- dput(nd->dentry);
- nd->dentry = path.dentry;
+ error = open_namei_create(nd, &path, flag, mode);
if (error)
goto exit;
- /* Don't check for write permission, don't truncate */
- acc_mode = 0;
- flag &= ~O_TRUNC;
- goto ok;
+ return 0;
}
/*
@@ -1926,30 +1944,32 @@ asmlinkage long sys_mkdirat(int dfd, const char __user *pathname, int mode)
{
int error = 0;
char * tmp;
+ struct dentry *dentry;
+ struct nameidata nd;
tmp = getname(pathname);
error = PTR_ERR(tmp);
- if (!IS_ERR(tmp)) {
- struct dentry *dentry;
- struct nameidata nd;
+ if (IS_ERR(tmp))
+ goto out_err;
- error = do_path_lookup(dfd, tmp, LOOKUP_PARENT, &nd);
- if (error)
- goto out;
- dentry = lookup_create(&nd, 1);
- error = PTR_ERR(dentry);
- if (!IS_ERR(dentry)) {
- if (!IS_POSIXACL(nd.dentry->d_inode))
- mode &= ~current->fs->umask;
- error = vfs_mkdir(nd.dentry->d_inode, dentry, mode);
- dput(dentry);
- }
- mutex_unlock(&nd.dentry->d_inode->i_mutex);
- path_release(&nd);
-out:
- putname(tmp);
- }
+ error = do_path_lookup(dfd, tmp, LOOKUP_PARENT, &nd);
+ if (error)
+ goto out;
+ dentry = lookup_create(&nd, 1);
+ error = PTR_ERR(dentry);
+ if (IS_ERR(dentry))
+ goto out_unlock;
+ if (!IS_POSIXACL(nd.dentry->d_inode))
+ mode &= ~current->fs->umask;
+ error = vfs_mkdir(nd.dentry->d_inode, dentry, mode);
+ dput(dentry);
+out_unlock:
+ mutex_unlock(&nd.dentry->d_inode->i_mutex);
+ path_release(&nd);
+out:
+ putname(tmp);
+out_err:
return error;
}
@@ -2048,10 +2068,11 @@ static long do_rmdir(int dfd, const char __user *pathname)
mutex_lock_nested(&nd.dentry->d_inode->i_mutex, I_MUTEX_PARENT);
dentry = lookup_hash(&nd);
error = PTR_ERR(dentry);
- if (!IS_ERR(dentry)) {
- error = vfs_rmdir(nd.dentry->d_inode, dentry);
- dput(dentry);
- }
+ if (IS_ERR(dentry))
+ goto exit2;
+ error = vfs_rmdir(nd.dentry->d_inode, dentry);
+ dput(dentry);
+exit2:
mutex_unlock(&nd.dentry->d_inode->i_mutex);
exit1:
path_release(&nd);
@@ -2191,30 +2212,33 @@ asmlinkage long sys_symlinkat(const char __user *oldname,
int error = 0;
char * from;
char * to;
+ struct dentry *dentry;
+ struct nameidata nd;
from = getname(oldname);
if(IS_ERR(from))
return PTR_ERR(from);
to = getname(newname);
error = PTR_ERR(to);
- if (!IS_ERR(to)) {
- struct dentry *dentry;
- struct nameidata nd;
+ if (IS_ERR(to))
+ goto out_putname;
- error = do_path_lookup(newdfd, to, LOOKUP_PARENT, &nd);
- if (error)
- goto out;
- dentry = lookup_create(&nd, 0);
- error = PTR_ERR(dentry);
- if (!IS_ERR(dentry)) {
- error = vfs_symlink(nd.dentry->d_inode, dentry, from, S_IALLUGO);
- dput(dentry);
- }
- mutex_unlock(&nd.dentry->d_inode->i_mutex);
- path_release(&nd);
+ error = do_path_lookup(newdfd, to, LOOKUP_PARENT, &nd);
+ if (error)
+ goto out;
+ dentry = lookup_create(&nd, 0);
+ error = PTR_ERR(dentry);
+ if (IS_ERR(dentry))
+ goto out_unlock;
+
+ error = vfs_symlink(nd.dentry->d_inode, dentry, from, S_IALLUGO);
+ dput(dentry);
+out_unlock:
+ mutex_unlock(&nd.dentry->d_inode->i_mutex);
+ path_release(&nd);
out:
- putname(to);
- }
+ putname(to);
+out_putname:
putname(from);
return error;
}
@@ -2300,10 +2324,11 @@ asmlinkage long sys_linkat(int olddfd, const char __user *oldname,
goto out_release;
new_dentry = lookup_create(&nd, 0);
error = PTR_ERR(new_dentry);
- if (!IS_ERR(new_dentry)) {
- error = vfs_link(old_nd.dentry, nd.dentry->d_inode, new_dentry);
- dput(new_dentry);
- }
+ if (IS_ERR(new_dentry))
+ goto out_unlock;
+ error = vfs_link(old_nd.dentry, nd.dentry->d_inode, new_dentry);
+ dput(new_dentry);
+out_unlock:
mutex_unlock(&nd.dentry->d_inode->i_mutex);
out_release:
path_release(&nd);
generated by cgit v1.2.3 (git 2.25.1) at 2024-05-02 21:39:18 +0000